Ops Manager Never Ping a Host which is Alive

Thank you for your reply @finisky. I tried your suggestion, however, it turns out the issue is different. After commenting here, I found AuthenticationFailed logs under mongodb-agent-monitoring logs. It was working totally fine. I just disabled backup and then ended up with this issue. I am still investigating it.

[2022-02-05T22:40:48.436+0000] [metrics.status.collector-ops-manager-db-2.ops-manager-db-svc.mongodb.svc.cluster.local:27017.error] [monitoring/collector.go:looper:254] Failure during status metrics collection.
Failed to get connectionStatus. Err: `connection() : auth error: sasl conversation error: unable to authenticate using mechanism "SCRAM-SHA-256": (AuthenticationFailed) Authentication failed.`
	at cm/monitoring/dialing.go:491
	at cm/monitoring/dialing.go:240
	at cm/monitoring/dialing.go:351
	at cm/monitoring/dialing.go:368
	at louisaberger/procexec/concurrency.go:45
	at src/runtime/asm_amd64.s:1374
[22:40:48.448] All 0 Mongo processes are in goal state. Monitoring in goal state

Here is my OpsManager manifest if it helps in any way to troubleshoot. I assume this automation user is being created by OpsManager itself, therefore, I don’t know how it was working now but not now.

---
apiVersion: mongodb.com/v1
kind: MongoDBOpsManager
metadata:
  name: ops-manager
  namespace: mongodb
spec:
  version: 4.4.9
  configuration:
    mms.centralUrl: https://mongodb.mydomain.com

  adminCredentials: ops-manager-admin-secret

  externalConnectivity:
    type: NodePort # TODO: should be service behind nginx ingress

  applicationDatabase:
    members: 3
    version: 4.2.11-ent
    persistent: true
    podSpec:
      persistence:
        single:  
          storage: 100G
          storageClass: aws-efs 
  backup:
    enabled: true
    opLogStores:
      - name: oplog1
        mongodbResourceRef:
          name: om-mongodb-oplog-db
        mongodbUserRef:
          name: ops-manager-app
    s3Stores:
    - name: "news3store"
      s3SecretRef:
        name: "REDACTED" 
      s3BucketEndpoint: "REDACTED"
      s3BucketName: "REDACTED"
      pathStyleAccessEnabled: true
---